You can find all the plugins in the WordPress.org directory that are reviewed to meet a certain level of quality before they are offered to you. However, there are free and paid plugins within the guide.
Premium or paid plugins may come with additional support and tutorials to help with the use of the plugin, while some free plugins may not.
A free version of the plugin may be offered as an incentive to upgrade to the premium version to gain access to the full range of functionality of the plugin. If you choose to install a free plugin, especially from sources outside of the WordPress directory, it is important to research the source.
Pay close attention to the plugin's compatibility with your version of WordPress and any concerns reported by existing users.
Before installing any plugins, you should do some homework to ensure that the plugin vendor is reputable and trustworthy. WordPress designers often say that whatever your site needs, there's a plugin for it — and many of them are safe, and completely free.
Always check browser compatibility, ratings, reviews and the latest updates before installing any plugins on your website. The power of WordPress allows you to select any combination of plugins you need for your website.